JP5688342B2 - Vibration cutting equipment - Google Patents

Description

  The present invention relates to a vibration cutting apparatus in which a main shaft to which a cutting tool is attached rotates at high speed while ultrasonically vibrating in the axial direction.

  Conventionally, as this type of vibration cutting apparatus, a structure shown in Patent Document 1 is generally used.

  In this device, a front end side and a driving side of a main shaft are supported by a housing via a bearing, a vibration unit for ultrasonically vibrating the main shaft in the axial direction on a base end side of the main shaft, and a driving device for rotating the main shaft And a cutting tool is attached to the tip side, and the spindle rotates while being ultrasonically vibrated, so that the workpiece can be cut.

  The excitation unit is configured to combine a plurality of types of piezoelectric elements and vibrate in the axial direction, torsional direction, or bending direction.

JP 2009-241225 A

  However, in Patent Document 1, since the axial vibration of the housing acts as a relative motion between the inner ring and the outer ring of the bearing, an undesired load more than necessary is always applied to the bearing. For this reason, there is a problem that the bearing is likely to be deteriorated and becomes a factor of deteriorating the maintainability.

  In addition, since the excitation unit is configured to vibrate in the axial direction, torsional direction, or bending direction by a plurality of piezoelectric elements, the structure of the piezoelectric element and the control device for controlling the piezoelectric element are complicated, increasing the size and cost. There is also a problem of inviting.

  An object of the present invention is to provide a vibration cutting apparatus that can be constructed simply, compactly, and inexpensively, and that can effectively improve reliability and durability.

  In order to achieve this object, the present invention takes the following measures.

  That is, the vibration cutting device of the present invention rotates a cutting tool attached to the tip side while ultrasonically vibrating in the axial direction, and includes a housing and a housing supported by the housing via a support mechanism. And a motor housed in the housing, a main shaft that is rotationally driven by the motor and to which the cutting tool is attached, and a vibration unit that vibrates the housing in the axial direction. Has a motion conversion unit that changes the rotational phase of the casing by using an operation in which the casing vibrates in the axial direction. In the motion conversion unit, vibration from the excitation unit is defined as the axial direction. It is characterized by demultiplexing in the circumferential direction.

  With this configuration, the axial vibration of the housing acts on the entire housing, including the motor, and does not significantly increase the bearing load inside the motor. Can be improved. In addition, since only the vibration in the axial direction is generated in the vibration unit, and a part of the vibration is demultiplexed into the vibration in the circumferential direction, the structure of the piezoelectric element or the like constituting the vibration unit and the control device for controlling this The structure becomes simple, which contributes to downsizing and cost reduction.

  In order to further simplify the structure, it is effective that the motion conversion unit demultiplexes part of the axial vibration into the circumferential vibration by using the twist of the twisting member. is there.

  In particular, in order to eliminate the need for correction of the tool diameter, it is desirable that a plurality of twist members are arranged at substantially equiangular positions around the axis.

  As a preferred embodiment, one having a wing shape that bends as the twisting member approaches the housing from the housing along the radial direction can be cited.

  Since the present invention has the configuration described above, it is possible to provide a new and useful vibration cutting apparatus that can be configured simply, compactly and inexpensively, and has improved reliability and durability effectively.

1 is an overall perspective view showing a vibration cutting device according to an embodiment of the present invention from the front side. The whole perspective view which shows the embodiment from the back side. FIG. 3 is an exploded perspective view of FIG. 2. The typical longitudinal section of the embodiment. The A section enlarged view in FIG. Action | operation explanatory drawing of the same embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  The vibration cutting apparatus (ultrasonic cutting apparatus) of this embodiment shown in FIGS. 1 to 3 supports a housing 2 to which a vibration unit 1 serving as an ultrasonic driving source is attached, via a support mechanism 3. Let me. The housing 4 serves as a pedestal for mounting the housing 2 and can take an appropriate form according to the application target.

  As shown in FIG. 4, the housing 2 has a hollow cylindrical portion 21 formed by processing a single member such as stainless steel or titanium alloy, and is integrated with the cylindrical portion 21 by appropriate means. A rear end portion 22 that is attached to the housing 2, and the vibration exciter 1 is configured by sandwiching the electrode 11 between a pair of piezoelectric elements 12 and 12. 22 and a pressing member 23 arranged further rearward of the excitation unit 1, and the piezoelectric elements 12 and 12 together with the electrode 11 are housed by a fastening screw 51 inserted into the pressing member 23. 2 is fastened together with the rear end 22. A feed line (not shown) for ultrasonically driving the piezoelectric element 12 is connected to the electrode 11, and the vibration direction of the piezoelectric element 12 is a direction along the axis m of the housing 2. Since the piezoelectric element 12 of this embodiment is cut off from the rotation of the motor 6 described below with the housing 2, an electrical sliding portion such as a brush is unnecessary.

  A motor 6 is incorporated in the housing 2. As shown in FIGS. 3 and 4, the motor 6 of this embodiment has an air supply port 61 and an exhaust port 62 as shown in FIGS. 3 and 4, and the main shaft 63 at the front end is rotationally driven by sending compressed air to the air supply port 61. This is a so-called air motor. The air supply port 61 and the exhaust port 62 are taken out through a notch portion 2 a provided in the housing 2 to a position where an external pipe (not shown) can be easily attached and detached. Since various things are known about the principle and structure of the air motor itself, explanation here is omitted.

  A chuck 7 is attached to the shaft end portion of the main shaft 63 by press fitting or the like. The chuck 7 has an attachment hole 71 at the tip, and a cutting tool 8 such as an end mill is attached to the attachment hole 71 so as to be integrally rotatable by shrink fitting or the like. Examples of the material of the cutting tool 8 include cemented carbide, sintered material, diamond, and a grinding wheel.

  The housing 4 is formed by aluminum die casting or the like, and is provided with a weight that does not affect vibration attenuation. The entire housing 4 has a rectangular parallelepiped shape as shown in FIG. In addition, a plate-like cutout portion 41 is formed, and a through hole 42 is formed at a position penetrating between the cutout portions 41, 41.

  On the other hand, the support mechanism 3 has a thickness and an outer shape corresponding to the notch portion 41 of the housing 4 and supports the casing 2 and a rectangular frame 31 fixed to two opposing surfaces of the housing 4 with screws v. Vibration that is arranged at a position where the load from the housing 2 acting on the housing support 32 and the load acting on the housing support 32 is transmitted to the frame 31 and demultiplexes part of the vibration in the direction of the axis m in different directions. It is comprised from the conversion part AL.

  The housing support portion 32 is integrally formed with a partially annular sandwiching portion 32a formed slightly larger than the outer shape of the housing 2, and arm portions 32b extending substantially radially from both ends of the sandwiching portion 32a. Therefore, a predetermined gap is formed between the arm portions 32b and 32b, and the arm portions 32b and 32b are urged in the direction of narrowing the gap, so that the holding portion 32a is reduced in diameter and the urging force is removed. Between the arm parts 32b and 32b, the clamping part 32a has elasticity which expands to the original shape. The ends of the arm portions 32b and 32b are closed.

  FIG. 5 is an enlarged view of portion A in FIG. The curved inclined blade 33 which is the main body of the vibration converting portion AL is a twisted member twisted between one end side and the other end side of the plate material, and the housing support portion 32a along the radial direction (radial direction) of the housing 2. And the frame 31 are attached at positions where they are connected. The curved blade 33 is curved with respect to the axis m on the base end side (refer to the broken line s1 in FIG. 5) whose cross section perpendicular to the radial direction is close to the axis m (see the broken line s1 in FIG. 5). 5 (see the broken line s2 in FIG. 5). In this embodiment, the two bent blades 33 are attached to the corners of the frame 31 by welding or the like with the tips parallel to the axis m, and the remaining one bent blade 33 is attached to the bottom of the frame 31. Are attached by welding or the like.

  That is, the housing 2 is inserted into the annular holding portion 32a of the housing support portion 32 and the through hole 42 of the housing 4, and the arm portions 32b and 32b of the housing support portion 32 at two locations in the axial center m direction. By tightening the gap with a screw 30 in the direction in which the gap is narrowed, the casing 2 has curved inclined blades 33 similarly twisted in the same direction at two locations in the axial center m direction as shown in FIGS. It is supported in a state where it floats from the inner periphery of the frame 31 and both opposing surfaces of the housing 4 via the main motion conversion part AL.

  With this configuration, when the electrode 11 is energized and the piezoelectric element 12 is vibrated in an ultrasonic region of, for example, about 40 kHz in the axial center m direction, the vibration conversion unit AL is applied in the radial direction (radial direction). The curved bevel blade 33, which is the main body of the main body, always regulates the position of the center of the casing 2 on the fixed axis m, and the curvature of the casing 2 as the casing 2 reciprocates in the axis m direction with respect to the circumferential direction. By oscillating depending on the side toughness (plasticity), a phase difference in the circumferential direction is generated in the main shaft 63 and thus in the cutting tool 8. For example, when a certain point on the housing 2 is at a position M in FIG. 6A at rest and this cross section is FIG. 6B, this is an arrow in FIG. 6A together with ultrasonic vibration. When a certain point moves from the M position to the A position by oscillating in the X direction, the housing 2 causes a phase displacement in one direction as shown in FIG. As shown in FIG. 4D, the casing 2 causes a phase displacement in the other direction when it moves from the position B to the position B. Such a phase change occurs at the same cycle as the ultrasonic frequency, and at the same time, the air motor 6 shown in FIG. 4 rotates the main shaft 63 at a predetermined speed, so that the cutting tool 8 attached to the main shaft 63 rotates at a predetermined speed. While rotating by a number, it reciprocates in the direction of the axis m at the ultrasonic frequency, and at the same time, causes a twisting motion toward the advance side and the delay side with respect to the circumferential direction.

  For this reason, if this vibration cutting device is used, the object to be processed has a grain boundary, for example, a fragile work material such as glass or ceramic, an ultra-high hardness such as carbon steel, stainless steel, or hardened steel. Cutting work can be performed on a work material or the like while effectively promoting crystal grain breakage.

  As described above, the vibration cutting apparatus of the present embodiment rotates the cutting tool 8 attached to the tip side while ultrasonically vibrating in the direction of the axis m, and includes a housing 4 and a support mechanism in the housing 4. 3, a housing 6 supported by the housing 2, a motor 6 accommodated in the housing 2, a main shaft 63 that is rotationally driven by the motor 6 and to which the cutting tool is attached, and a center of the housing 2. a vibration converting unit 1 that vibrates in the m direction, and the support mechanism 3 changes the rotational phase of the casing 2 using an operation in which the casing 2 vibrates in the direction of the axis m. An AL is provided, and the vibration from the excitation unit 1 is demultiplexed into the axial center m direction and the circumferential direction in the motion conversion unit AL.

  With this configuration, the vibration in the direction of the axis m of the housing 2 acts on the entire housing 2 including the motor 6 and the bearing load inside the motor 6 is not greatly increased. It is possible to effectively improve the maintainability by preventing the deterioration of the resin. Moreover, since only the vibration in the axial center m direction is generated in the vibration unit 1 and a part of the vibration is demultiplexed into the vibration in the circumferential direction, the structure of the piezoelectric element 12 and the like constituting the vibration unit 1 and the control thereof are controlled. Therefore, the configuration of the control device is simplified, which contributes to downsizing and cost reduction.

  Further, the motion conversion unit AL uses a twist of the curved inclined blade 33 which is a twisting member to demultiplex a part of the vibration in the axial direction into the vibration in the circumferential direction. In addition, since the guide groove and the like are not necessary, the structure can be further simplified.

  In particular, a plurality of curved inclined blades 33, which are twisting members, are arranged at substantially equiangular positions around the axial center m so that each twisting member performs the same twisting operation. Can be held in. For this reason, the movement of the casing 2 and the cutting tool 8 in the radial direction can be eliminated, and the correction of the tool diameter can be made unnecessary.

  Further, the bend blade 33 that is a twisting member has a shape that bends as it approaches the housing 2 from the housing 4 along the radial direction. An effective twisting motion is exhibited.

  The specific configuration of each unit is not limited to the above-described embodiment.

  For example, in the above embodiment, the twist members are arranged at three equiangular positions around the axis of the housing, but may be two equiangular places or four or more equiangular positions.

  Further, the shape of the twisting member is not limited to the configuration shown in the drawing as long as it can perform a demultiplexing operation.

  In addition, the main shaft and the tool mounting structure can be variously modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Excitation part 2 ... Housing 3 ... Support mechanism 6 ... Motor 8 ... Cutting tool 33 ... Torsion member (curved blade)
63 ... Spindle AL ... Motion converter m ... Axis center

Claims (4)

A vibration cutting device that rotates a cutting tool while ultrasonically vibrating in an axial direction,
A housing, a housing supported by the housing via a support mechanism, a motor housed in the housing, a main shaft that is rotationally driven by the motor and on which the cutting tool is attached, and a shaft An excitation unit that vibrates in the direction of the heart,
The support mechanism includes a motion conversion unit that changes a rotation phase of the casing by using an operation in which the casing vibrates in an axial direction. In the motion conversion unit, the vibration from the excitation unit is pivoted. A vibration cutting apparatus characterized by demultiplexing into a central direction and a circumferential direction. The vibration cutting device according to claim 1, wherein the motion conversion unit demultiplexes part of the vibration in the axial direction into vibration in the circumferential direction using the twist of the twist member. The vibration cutting apparatus according to claim 2, wherein a plurality of twist members are arranged at substantially equiangular positions around the axis. 4. The vibration cutting device according to claim 3, wherein the twisting member has a blade shape that bends as it approaches the casing from the housing along the radial direction.

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